1. Field of the Invention
The invention relates in general to a discrimination method of an optical storage medium, and more particularly, to a method of discriminating the data storage format of the optical storage medium, according to the physical characteristics of various data storage formats thereof.
2. Related Art of the Invention
The optical storage media have been continuously retrofitted by versatile developments of related technologies. Nowadays, digital versatile disks (DVD) and compact disks (CD) are the two major types of optical storage media, which have been mass-produced and broadly for sale on the market. Many manufacturers devote their efforts to develop their optical pickup head with capability of reading data from both types of the optical storage media aforementioned. However, since these two types of optical storage media have different physical characteristics and data storage formats, any optical device essentially has the capable of discriminating the type of the currently loaded optical storage medium.
For example, an optical disk system (e.g. DVD-ROM drive or DVD-ROM/CDRW (i.e. Combo) drive) may assume the optical storage medium that its pickup head currently accessed is a DVD and use the parameters required for reading a DVD to drive its pickup head for reproducing data. Once the data cannot be reproduced under such an assumption, the optical pickup head is reset and loads associated parameters for reading a CD before driving the pickup head for reproducing data again. However, since the operations including light source turning on, lens focusing and tracking, must be performed before accessing data for confirming the assumption, time-cost is arisen for re-performing the aforementioned operations if the assumption is incorrect. Time-consumption that the optical pickup head discriminates the type of the optical storage medium may vary seriously and very difficult to control, customers may confuse that with system damage or malfunction.